Robosub 2016 – Day 7: The Semi Finals

Today was the first day of semi final and our static judging. The judging was at 8h15 and the semi final was scheduled to go at 1h30 pm in on the B size (north-east portion of the Transdec).

Before that, we had the chance to have two tests. Yesterday’s investment in a hacked simulator really paid off. Before we hit the water, we were able to discover some small bugs that would have prevented correct mission execution. The first test, we perfectly did the sequence gate-pipe-mapping buoys with the sonar. However, we were too far from the buoys to align correctly. It was a calibration issue. We restarted but were not able to select the correct map target. We used to select targets based on difference with the pipe’s angle. We changed that for selecting the nearest target to the submarine.

We tested those changes in the second test. Out of 4 tries, we achieved 3 perfect buoy mission. Big success for the team since it used everything we did this year. It was a real autonomous run, with only cameras and sonar and no predefined zone.

The missed try was a mystery as why it failed. For now, we believed it is a loophole that happens when we used to see the pipe but lose it afterward. We did not have time to fix this, since we were near our semi-final time.

The semi-final did not work as expected. We hoped we’d be able to reproduce the exact sequence that worked 3 times perfectly less than 1 hour before. It turned out that the buoys are way closer to the gate than when we tested, rending the sonar unreliable. We trigged on a wall and start going towards it. We brought back the sub to try it again, but this time, it seems the bug from the previous test showed up again on all successive runs. We tried to hack our way through, but were not able to quickly all our mission logic and score some point.

There is a lot of tests reserved today, so we won’t be able to get other test time. We’ll go to the hotel, catch-up some shut-eye and try to figure out our bug. We’ll review all the workflow prepare a no-guts-no-glory mission just in case. We hope to do well enough tomorrow to get to the final. If not, we might get a wildcard on Sunday, but it won’t be necessary.